The present invention relates to late transition metal complexes; a process for their preparation and their use in the polymerization of olefins.
The papers Organometallics, 10, 1421-1431, 1991; Inorg. Chem., 34, 4092-4105, 1995; J. Organomet. Chem., 527(1-2), 263-276, 1997; and Inorg. Chem., 35(6), 1518-28, 1996, report the reaction of bis (iminophosphoranyl) methane (BIPM) which are typically aryl substituted on the phosphorus atom and the nitrogen with group VIII metal halides (chlorides) further comprising at two weakly coordinating ligands (L) such as nitriles or cyclooctadiene, afforded several products depending on the reaction time, type of ligand or nature of the metal. The product could be a Nxe2x80x94C chelating type product or a Nxe2x80x94N chelating product (similar to those of the present invention). 
The products contain alkyl bridge between the phosphinimine groups and the references do not disclose the tridentate transition metal complexes of the present invention. Further, none of the references teach or suggest the use of such compounds for the polymerization of alpha olefins.
U.S. Pat. No. 5,557,023 issued Sep., 1996 teaches the use of some phosphinimines complexes to oligomerize alpha olefins. However, the complexes disclosed are not bis-imine complexes. Rather, the complexes are of the structure indicated below. 
wherein R, Q, etc. are as defined in the patent. The structures disclosed in the patent are not the bis-imines of the present invention. While the reference does teach oligomerization, it does not suggest polymerization.
WO 98/30609 patent application published Jul. 16, 1998 assigned to E. I. Du Pont de Nemours teaches the use of various complexes of nickel to polymerize alpha olefins. A close complex in the disclosure is compound XXXXI at the middle of page 9 and the associated description of the various substituents. While, the compound contains a cyclic bridge, a nickel heteroatom completes the cyclic bridge in the middle of the compound. The reference does not contemplate or disclose compounds of the present invention which have a tridentate functionality. The reference fails to disclose the subject matter of the present invention.
There are a number of patents and papers by Brookhart and/or Gibson disclosing the use of pyridine bridged bis-amine Group 8, 9 or 10 metals to polymerize olefins. However, such papers teach that copolymers are not produced (e.g. WO 98/27124). The present invention proved copolymers of olefins made using an iron (or cobalt) based catalyst.
WO 98/47933 published Oct. 29, 1998 to MacKenzie et al, assigned to Eastman Chemical Company teaches bidentate amino-imine complexes of iron, cobalt, nickel and palladium for the polymerization of olefins. The complexes do not contemplate the presence of a sulfur, oxygen or phosphorus atom in the ligand bound to the iron, cobalt, nickel or palladium metal atom. As such the reference teaches away from the subject matter of the present invention.
WO 98/49208 published Nov. 5, 1998 in the name of Bres et al, assigned to BP Chemicals Limited also discloses an amino-imine complex of nickel or palladium for the polymerization of alpha olefins. Again the reference teaches away from the subject matter of the present invention in that it does not teach nor suggest the presence of a sulfur, oxygen or phosphorus atom bound to the metal atom in the complex.
The present invention provides a ligand of formula I: 
wherein W is selected from the group consisting of a sulfur atom, an oxygen atom and a phosphorus atom; Y and Z are independently selected from the group consisting of a carbon atom, a phosphorus atom and a sulfur atom; when Y is phosphorus m is 2, when Y is carbon or sulfur m is 1; when Z is phosphorus n is 2, when Z is carbon or sulfur n is 1; each R is independently selected from the group consisting of a hydrogen atom, and a hydrocarbyl radical or R taken together with Q may form a cyclic hydrocarbyl; R1 and R2 are independently selected from the group consisting of a hydrogen atom, a substituted or unsubstituted hydrocarbyl radical which may contain one or more heteroatoms, preferably consisting of the group selected from silicon, boron, phosphorus, nitrogen and oxygen which may be bound directly or indirectly to the nitrogen atoms and a tri-C1-4 alkyl silyl radical; Q is a divalent unsaturated hydrocarbyl radical or a divalent radical comprising hydrogen, carbon and one or more heteroatoms selected from the group consisting of an oxygen atom, a nitrogen atom, a sulfur atom and a boron atom, and Q when taken together with W forms one or more unsaturated rings, which unsaturated cyclic rings may be unsubstituted or may be fully substituted by one or more substituents independently selected from the group consisting of a halogen atom and an alkyl radical.
The present invention further provides a process for the polymerization of one or more C2-12 alpha olefins in the presence of an activated complex of formula II: 
wherein M is a Group 8, 9 or 10 metal; W is selected from the group consisting of a sulfur atom, an oxygen atom and a phosphorus atom; Y and Z are independently selected from the group consisting of a carbon atom, a phosphorus atom and a sulfur atom; when Y is phosphorus m is 2, when Y is carbon or sulfur m is 1; when Z is phosphorus n is 2, when Z is carbon or sulfur n is 1; each R is independently selected from the group consisting of a hydrogen atom, and a hydrocarbyl radical or R taken together with Q may form a cyclic hydrocarbyl; R1 and R2 are independently selected from the group consisting of a hydrogen atom, a substituted or unsubstituted hydrocarbyl radical which may contain one or more heteroatoms, preferably consisting of the group selected from silicon, boron, phosphorus, nitrogen and oxygen which may be bound directly or indirectly to the nitrogen atoms and a tri-C1-4 alkyl silyl radical; Q is a divalent unsaturated hydrocarbyl radical or a divalent radical comprising hydrogen, carbon and one or more heteroatoms selected from the group consisting of an oxygen atom, a nitrogen atom, a sulfur atom and a boron atom, and Q when taken together with W one or more unsaturated rings, which unsaturated cyclic rings may be unsubstituted or may be fully substituted by one or more substituents independently selected from the group consisting of a halogen atom and an alkyl radical, L is an activatable ligand and p is an integer from 1 to 3.
In a further aspect, the present invention provides a process for reacting one or more C2-12 alpha olefins in a nonpolar solvent in the presence of the above catalyst with an activator at a temperature from 20xc2x0 C. to 250xc2x0 C.; and at a pressure from 15 to 15000 psi.
The term xe2x80x9cscavengerxe2x80x9d as used in this specification is meant to include those compounds effective for removing polar impurities from the reaction solvent. Such impurities can be inadvertently introduced with any of the polymerization reaction components, particularly with solvent, monomer and catalyst feed; and can adversely affect catalyst activity and stability. It can result in decreasing or even elimination of catalytic activity, particularly when an activator capable of ionizing the Group 8, 9 or 10 metal complex is also present.
The term xe2x80x9can inert functional groupxe2x80x9d means a functional group on a ligand or substituent which does not participate or react in the reaction. For example in the polymerization aspect of the present invention an inert functional group would not react with any of the monomers, the activator or the scavenger of the present invention. Similarly for the alkylation of the metal complex or the formation of the metal complex the inert functional group would not interfere with the alkylation reaction or the formation of the metal complex respectively.
As used in this specification an activatable ligand is a ligand removed or transformed by an activator. These include anionic substituents and/or bound ligands.
In the compounds of formula 11 above, preferably M is a Group 8, 9 or 10 metal. Preferably M is selected from the group of Group 8, 9 or 10 metals consisting of Fe, Co, Ni or Pd.
In the above compounds of formula I and II each R is independently selected from the group consisting of a hydrogen atom and hydrocarbyl radical. Preferably R is selected from the group consisting of C1-10 alkyl or aryl radicals, most preferably C1-4 radicals such as a bulky t-butyl radical and phenyl radicals. In the above formula I and II, R1 and R2 are independently selected from the group consisting of a hydrocarbyl radical preferably a phenyl radical which is unsubstituted or substituted by up to five hydrocarbyl radicals which may contain one or more inert functional groups, preferably C1-4 alkyl radicals, or a C1-10 alkyl radical, or two hydrocarbyl radicals taken together may form a ring, or tri alkyl silyl radical, preferably C1-6 , most preferably C1-4 silyl radical. Preferably R may be a 2,6-diisopropyl phenyl radical or a trimethyl silyl radical. In the complex of formula II above, L is an activatable ligand preferably a halide atom or a C1-6 alkyl or alkoxide radical, most preferably a halide atom (Cl or Br) and p is from 1 to 3, preferably 2 or 3.
In the compounds of formula I and II the unsaturated rings structure formed by Q taken together with W may form one or more a 5 to 10 membered ring(s) (i.e. Q contains from 4 to 9 atoms). As noted above not all of the atoms in the backbone of Q need to be carbon atoms. Q may contain one or more heteroatoms selected from the group consisting of an oxygen atom, a nitrogen atom, a sulfur atom and a boron atom. The resulting ring structure may be unsubstituted or up to fully substituted by one or more substituents selected from the group consisting of a halogen atom, preferably chlorine and a Ci alkyl radical.
In the above formulas I and II, R may be taken together with Q to form a cyclic hydrocarbyl structure, preferably an aromatic ring. If W is a sulfur atom then Q taken with the W may form rings such as thiophene, dithiole, thiazole and thiepin. If Q taken together with one R forms a cyclic hydrocarbyl then the structure may be benzothiophene. These unsaturated rings may be unsubstituted or up to fully substituted by one or more substituents selected from the group consisting of a halogen atom, preferably chlorine and a C1-4 alkyl radical.
If W is an oxygen atom then Q taken with the W may form rings such as furan, oxazole, oxidiazole, pyran, dioxin, oxazine and oxepin. If Q taken together with one R forms a cyclic hydrocarbyl then the structure may be benzofuran, benzoxazole and benzoxazine. If both R""s are taken together with Q and W the structure could be xanthene. These unsaturated rings may be unsubstituted or up to fully substituted by one or more substituents selected from the group consisting of a halogen atom, preferably chlorine and a C1-4 alkyl radical.
If W is a phosphorus atom then the phosphorus homologues of the above oxygen and sulfur rings would be obtained.
In the above compounds, Z and Y may independently be selected from the group consisting of a carbon atom, an oxygen atom or a phosphorus atom. Preferably Z and Y are the same. Most preferably Z and Y are phosphorus atoms.
The metal complexes of the present invention may be prepared by reacting the ligand with a compound of MXn xe2x80xa2A (H2O), where X may be selected from the group consisting of halogen, C1-6 alkoxide, nitrate or sulfate, preferably halide and most preferably chloride or bromide, and A is 0 or an integer from 1-6.
The reaction of the complex of formula I with the compound of the formula MXn xe2x80xa2A (H2O) may be conducted in a hydrocarbyl solvent or a polar solvent such as THF (tetrahydrofuran) or dichloromethane at temperature from 20xc2x0 C. to 250xc2x0 C., preferably from 20xc2x0 C. to 120xc2x0 C.
The resulting compound (i.e. formula II) may then be alkylated (either partially or fully). Some alkylating agents include alkyl aluminum reagents such as trialkyl aluminum, alkyl aluminum halides (i.e. (R)xAIX3xe2x88x92x wherein R is a C1xe2x80x83alkyl radical, X is a halogen, x is 1 or 2 and MAO as described below).
Solution polymerization processes are fairly well known in the art. These processes are conducted in the presence of an inert hydrocarbon solvent typically a C5-12 hydrocarbon which may be unsubstituted or substituted by C1-4 alkyl group such as pentane, hexane, heptane, octane, cyclohexane, methylcyclohexane or hydrogenated naphtha. An additional solvent is Isopar E (C8-12 aliphatic solvent, Exxon Chemical Co.).
The polymerization may be conducted at temperatures from about 20xc2x0 C. to about 250xc2x0 C. Depending on the product being made, this temperature may be relatively low such as from 20xc2x0 C. to about 180xc2x0 C. The pressure of the reaction may be as high as about 15,000 psig for the older high pressure processes or may range from about 15 to 4,500 psig.
Suitable olefin monomers may be ethylene and C3-20 mono- and di-olefins. Preferred monomers include ethylene and C3-12 alpha olefins which are unsubstituted or substituted by up to two C1-6 alkyl radicals, C8-12. Illustrative non-limiting examples of such alpha olefins are one or more of propylene, 1-butene, 1-pentene, 1-hexene, 1-octene and 1-decene.
The reaction product of the present invention may be a co- or homopolymer of one or more alpha olefins. The polymers prepared in accordance with the present invention have a good molecular weight. That is, weight average molecular weight (Mw) will preferably be greater than about 50,000 ranging up to 106, preferably 105 to 106.
The polyethylene polymers which may be prepared in accordance with the present invention typically comprise not less than 60, preferably not less than 70, most preferably not less than 80, weight % of ethylene and the balance of one or more C4-10 alpha olefins, preferably selected from the group consisting of 1-butene, 1-hexene and 1-octene. The polyethylene prepared in accordance with the present invention may contain branching (e.g. one or more branches per 1000 carbon atoms, preferably 1-20 branches per 1000 carbon atoms, typically 1-10 branches per 1000 carbon atoms.
The activator may be selected from the group consisting of:
(i) an aluminoxane; and
(ii) an activator capable of ionizing the Group 8, 9 or 10 metal complex (which may be used in combination with an alkylating activator). The aluminoxane activator may be of the formula (R20)2AlO(R20AlO)mAl(R20)2 wherein each R20 is independently selected from the group consisting of C1-20 hydrocarbyl radicals, m is from 0 to 50, and preferably R20 is a C1-4 alkyl radical and m is from 5 to 30. The aluminoxane activator may be used prior to the reaction but preferably in situ alkylation is typical (e.g. alkyl groups replacing leaving ligands, hydrogen or halide groups).
If the Group 8, 9 or 10 metal complex is activated only with aluminoxane, the amount of aluminoxane will depend on the reactivity of the alkylating agent. Activation with aluminoxane generally requires a molar ratio of aluminum in the activator to the Group 8, 9 or 10 metal in the complex from 50:1 to 1000:1. MAO may be at the lower end of the above noted range.
The activator of the present invention may be a combination of an alkylating activator which also serves as a scavenger other than aluminoxane in combination with an activator capable of ionizing the Group 8, 9 or 10 complex.
The alkylating activator (which may also serve as a scavenger) may be selected from the group consisting of: (R)pMgX2xe2x88x92p wherein X is a halide, each R is independently selected from the group consisting of C1-10 alkyl radicals, preferably C1-8 alkyl radicals and p is 1 or 2; RLi wherein R is as defined above; (R)qZnX2xe2x88x92q wherein R is as defined above, X is halogen and q is 1 or 2; (R)sAlX3xe2x88x92s wherein R is as defined above, X is halogen and s is an integer from 1 to 3. Preferably in the above compounds, R is a C1-4 alkyl radical and X is chlorine. Commercially available compounds include triethyl aluminum (TEAL), diethyl aluminum chloride (DEAC), dibutyl magnesium ((Bu)2Mg) and butyl ethyl magnesium (BuEtMg or BuMgEt).
The activator capable of ionizing the Group 8, 9 or 10 metal complex may be selected from the group consisting of:
(i) compounds of the formula [R15]+[B(R18)4]xe2x88x92 wherein B is a boron atom, R15 is a cyclic C5-7 aromatic cation or a triphenyl methyl cation and each R18 is independently selected from the group consisting of phenyl radicals which are unsubstituted or substituted with from 3 to 5 substituents selected from the group consisting of a fluorine atom, a C1-4 alkyl or alkoxy radical which is unsubstituted or substituted by a fluorine atom; and a silyl radical of the formula xe2x80x94Sixe2x80x94 (R19)3 wherein each R19 is independently selected from the group consisting of a hydrogen atom and a C1-4 alkyl radical; and
(ii) compounds of the formula [(R16)tZH]+[B(R18)4]xe2x88x92 wherein B is a boron atom, H is a hydrogen atom, Z is a nitrogen atom or phosphorus atom, t is 2 or 3 and R16 is selected from the group consisting of C1-8 alkyl radicals, a phenyl radical which is unsubstituted or substituted by up to three C1-4 alkyl radicals, or one R16 taken together with the nitrogen atom to form an anilinium radical and R8 is as defined above; and
(iii) compounds (activators) of the formula B(R18)331  wherein R18 is as defined above.
In the above compounds preferably R18 is a pentafluorophenyl radical, R15 is a triphenylmethyl cation, Z is a nitrogen atom and R16 is a C1-4 alkyl radical or R16 taken together with the nitrogen atom forms an anilinium radical which is substituted by two C1-4 alkyl radicals.
The activator capable of ionizing the Group 8, 9 or 10 metal complex abstracts one or more L1 ligands so as to ionize the Group 8, 9 or 10 metal center into a cation, but not to covalently bond with the Group 8, 9 or 10 metal, and to provide sufficient distance between the ionized Group 8, 9 or 10 metal and the ionizing activator to permit a polymerizable olefin to enter the resulting active site.
Examples of compounds capable of ionizing the Group 8, 9 or 10 metal complex include the following compounds:
triethylammonium tetra(phenyl)boron,
tripropylammonium tetra(phenyl)boron,
tri(n-butyl)ammonium tetra(phenyl)boron,
trimethylammonium tetra(p-tolyl)boron,
trimethylammonium tetra(o-tolyl)boron,
tributylammonium tetra(pentafluorophenyl )boron,
tributylammonium tetra(pentafluorophenyl)boron,
tri(n-butyl)ammonium tetra (o-tolyl)boron
N,N-dimethylanilinium tetra(phenyl)boron,
N,N-diethylanilinium tetra(phenyl)boron,
N,N-diethylanilinium tetra(phenyl)n-butylboron,
N,N-2,4,6-pentamethylanilinium tetra(phenyl)boron
di-(isopropyl)ammonium tetra(pentafluorophenyl)boron,
dicyclohexylammonium tetra (phenyl)boron
triphenylphosphonium tetra)phenyl)boron,
tri(methylphenyl)phosphonium tetra(phenyl)boron,
tri(dimethylphenyl)phosphonium tetra(phenyl)boron,
tropillium tetrakispentafluorophenyl borate,
triphenylmethylium tetrakispentafluorophenyl borate,
benzene (diazonium) tetrakispentafluorophenyl borate,
tropillium phenyltris-pentafluorophenyl borate,
triphenylmethylium phenyl-trispentafluorophenyl borate,
benzene (diazonium) phenyltrispentafluorophenyl borate,
tropillium tetrakis (2,3,5,6-tetrafluorophenyl) borate,
triphenylmethylium tetrakis (2,3,5,6-tetrafluorophenyl) borate,
benzene (diazonium) tetrakis (3,4,5-trifluorophenyl) borate,
tropillium tetrakis (3,4,5-trifluorophenyl) borate,
benzene (diazonium) tetrakis (3,4,5-trifluorophenyl) borate,
tropillinum tetrakis (1,2,2-trifluoroethenyl) borate,
triphenylmethylium tetrakis (1,2,2-trifluoroethenyl) borate,
benzene (diazonium) tetrakis (1,2,2-trifluoroethenyl) borate,
tropillium tetrakis (2,3,4,5-tetrafluorophenyl) borate,
triphenylmethylium tetrakis (2,3,4,5-tetrafluorophenyl) borate, and
benzene (diazonium) tetrakis (2,3,4,5-tetrafluorophenyl) borate.
Readily commercially available activators which are capable of ionizing the Group 8, 9 or 10 metal complexes include:
N,N- dimethylaniliniumtetrakispentafluorophenyl borate;
triphenylmethylium tetrakispentafluorophenyl borate; and
trispentafluorophenyl boron.
If the Group 8, 9 or 10 metal complex is activated with a combination of an aluminum alkyl compound (generally other than aluminoxane), and a compound capable of ionizing the Group 8, 9 or 10 metal complex (e.g. activators (I) and (III) above) the molar ratios of Group 8, 9 or 10 metal:metal in the alkylating agent (e.g. Al); metalloid (e.g. boron or phosphorus) in the activator capable of ionizing the Group 8, 9 or 10 metal complex (e.g. boron) may range from 1:1:1 to 1:100:5. Preferably, the alkylating activator is premixed/reacted with the Group 8, 9 or 10 metal complex and the resulting alkylated species is then reacted with the activator capable of ionizing the Group 8, 9 or 10 metal complex.
In a solution polymerization the monomers are dissolved/dispersed in the solvent either prior to being fed to the reactor, or for gaseous monomers, the monomer may be fed to the reactor so that it will dissolve in the reaction mixture. Prior to mixing, the solvent and monomers are generally purified to remove polar moieties. The polar moieties or catalyst poisons include water, oxygen, metal impurities, etc. Preferably steps are taken before provision of such into the reaction vessel, for example by chemical treatment or careful separation techniques after or during the synthesis or preparation of the various components. The feedstock purification prior to introduction into the reaction solvent follows standard practices in the art (e.g. molecular sieves, alumina beds and oxygen removal catalysts) are used for the purification of ethylene, alpha olefin and optional diene. The solvent itself as well (e.g. cyclohexane and toluene) is similarly treated. In some instances, out of an abundance of caution, excess scavenging activators may be used in the polymerization process.
The feedstock may be heated prior to feeding into the reactor. However, in many instances it is desired to remove heat from the reactor so the feed stock may be at ambient temperature to help cool the reactor.
Generally, the catalyst components may be premixed in the solvent for the reaction or fed as separate streams to the reactor. In some instances premixing is desirable to provide a reaction time for the catalyst components prior to entering the reaction. Such an xe2x80x9cin line mixingxe2x80x9d technique is described in a number of patents in the name of Novacor Chemicals (International) S.A. (now known as NOVA Chemicals (International) S.A.) acquired from DuPont Canada Inc. For example it is described in U.S. Patent 5,589,555 issued Dec. 31, 1996.
The reactor may comprise a tube or serpentine reactor used in the xe2x80x9chigh pressurexe2x80x9d polymerizations or it may comprise one or more reactors or autoclaves. It is well known that the use in series of two such reactors each of which may be operated so as to achieve different polymer molecular weight characteristics. The residence time in the reactor system will depend on the design and the capacity of the reactor. Generally the reactors should be operated under conditions to achieve a thorough mixing of the reactants. On leaving the reactor system the solvent is removed and the resulting polymer is finished in a conventional manner.